The muslim armies need to fight the jews. This is the requirement from Islam.

Fight in the cause of Allah those who fight you but do not transgress limits; for Allah does not love transgressors. And slay them wherever you catch them and turn them out from where they have turned you out; for tumult and oppression are worse than slaughter. [TMQ Baqara:190- 191]

Therefore, if anyone transgresses a prohibition and attacks you, retaliate with the same force. (TMQ Baqara:194)